A Beckman spinning cup protein sequencer is required for completion of the research programs of several investigators. The sites of protein mistranslation are to be quantitatively determined when bacterophage MS2 coat protein is made in infected starved E.coli. Frequency of substitution of Asn for Lys and Leu for Phe will be determined for specific sites in the sequence of the protein. Thus, the frequency of mistranslation of specific codons will be ascertained. The complete primary structure of the bovine photoreceptor protein, rhodosin, is to be elucidated. Two large fragments, F1 and F2 of the protein will be prepared by limited proteolysis of rhodopsin in retinal disc membranes. Both F1 and F2 will be chemically and enzymatically cleaved to produce large peptides, the sequence of which will produce overlaps required to obtain the total primary structure of the protein. The functional significance of precursor sequences in the three adenovirus structural proteins: P-VII, P-VI and P-VIII will be investigated through sequence determinations. These precursor proteins are processed at the final stage of adenovirus assembly and is obligatory to the production of infections virus particles. Since all adenovirus proteins appear to be blocked at their N-termini, and unavilable for automatic sequencing, a radioactive sequencing protocol will be developed to enable the sequencing of all adenovirus proteins.